Valve-operating mechanism for internal-combustion engines



Dec. 7 1926. 1,609,711

w. M. GOODWIN VALVE OPERATING MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed April 26, 1926 ZV/O) mullul Patented Dec. 7, 1926.

'WIjLLIAM IVI. GOGDWIN, 0F CENTRAL SQUARE, NEW YGRK.

VALVE-OPERATING MECHANISM FOR- INTERNAL-GOMBUSTION ENGINES.

Application filed April 26, 1926. Serial No. 104,646.

This invention relates to a valve operating mechanism for internal combustion engines of the class set forth in my Patents 1,270,941, July 2,1918, and 1,500,556, July 8, 1924i, and 1,577,965, M'arch 23, 1926,: in so farthat the main object is to maintain -uninterrupted connection between each spring closed poppet valve and its lifting means so that all of the parts necessary to the opera. tion of the valve may move freelyyet positively with a minimumlost motion and thereby to rendersuch operation substantially noiseless. c i I a The present invention, however, relates more particularly to the use of a takeup wedge between the valve stem and itsoperating cam adjustableabout an axis parallel with and at oneflside of the axis of the valve and havinga slightly angular adjustment about said axis to compensate for variations in the length of, the valve stem due to varying temperatures and'wear in a manner somewhatisimilar to that set forth in my Patent 1,577,965.

1 The main object of the presentinvention isto provide means for effecting a positive angular movement of the wedge against the action of a suitable retracting spring to assure a positive seating-of the valve by its retracting spring at-cthe proper time without breaking the connection between the cam and valve stem. r e v Other objects and uses relating to specific parts of the device will be brought out in the following description." J In the drawings: I a V Figure 1 is a vertical sectional view, partly in elevation of aipop pet valve audits operating mechanism together *with' adjacent portions of the frame of an internal combustion engine, the valve being shown angular motion of thewedge in reverse di- 'rections."

This device is adapted to be used more particularly in connection with a. poppet valve l of an internal combustion engine 2- in which the valve l is opened and closed to and from itsseat 3 by means of a cam i4 and a retracting spring 5 respectively.

The valve 1-- and its retract-ing spring 5- may be of any well-known construction but asshown the valve stem is recip tion. 7

Lost motion take-up.

Suitable means is provided for maintaining uninterrupted connection between the cam 4iand valve stem as -1 to prevent lost motion and thereby to render the valve operating means substantially noiseless.

For this latter purpose a cylindrical member 8 is mounted for reciprocal axial and angular movement in'a suitable guide bearing 9 011 the engine frame between the'cam iand lower end of the valve stem 1 with its axis atone side of and parallel with the axis of the valve stem which latter is preferably arranged directly over the axis of the cam shaft as -4:.

That is, the cylindrical member 8 is preferably tubular and offset transversely of the axes of the cam shaft +5! and valve' stem '-1, a distance suflicient to bring one side thereof in a direct line between said axes for transmitting lifting motion from the cam 4 to the valve against the action of the retracting spring 5. V V

The cylindrical member 8 is preferably composed of lower and upper co-axial sections 8 and '8, the lower section -8"- being provided at its lower end with an'oflset bearing member -10 resting upon the perimeter of the cam The upper section 8 ournaled in and upon the upper endof the section --8-"- and is provided with an oli'sct inclined hearing or wedge surface --11-- on its upper end face and at the same side of its axis as the lower bearing member l0 for engaging the lower end face of the valve stem 1-, said wedge surface being elongated circuinferentially for maintaining contact with the lower end of the valve stem during the limited angular movement of the member -8-- and -S".

The bearing member 10 and wedge surface -11-- are arranged in a direct line between the axes of the cam shaft -'tand valve stem -1-, the lower face of the bearing member 1() being convexed transversely of the shaft to maintain a line contact with the cam -f in all positions of rotation of the cam surface.

A pair of cam flanges -12-- are rigidly secured to the cam shaft 4: co-axial therewith and at opposite ends of the cam iand also at opposite sides of the lower end of the bearing member -10-- with which they are adapted to engage.

The inner faces of these flanges -12- are provided with more or less abrupt cam surfaces 13- and 13- in axial almoment and inclined in the same direction thereby forming between them whatmay be termed a cam groove of substantially the same axial length as the corresponding width of the offset bearing member -10- so that the cam surfaces 13- and 13 may ride against opposite faces of the hear: ing member 10- during the rotation of thecain shaft in the direction indicated by arrow -m-, Figures 1 and 2.

These cam surfaces 13 and 13- are parallel and gradually return circumferentially from their high points to the lower points as indicated as in Figure 5, the high points of said cam surfaces being arranged nearly opposite the high point of the cam 4tor at the lower end of said cam and in such relation thereto as to cause aslight turning movement of the wedge surface 11- toward the upper end of the incline to register a lower point of the wedge with the adjacent end of the valve stem and thereby to assure the complete crossing of the valve at the proper time or immediately following the lifting of the valve by the high point of the cam.

The portion of the periphery of the cam e opposite its high point and immediately following the high points of the cams 13- and 13 are concentric with the axis of the cam shaft to allow the valve to dwell in its closed position during the fuel intake and period of combustion if it is the exhaust valve or during the exhaust and period of combustion if it is the intake valve.

The opposite side faces of the bearing member --10 are preferably convexed transversely of the shaft &'- to assure line contacts with the cam surfaces -13- and l3 and also to permit those cam surfaces to ride freely past the bearing member during the rotation of the cam shaft.

Suitable means is provided for automatically turning the wedge member -8 about its axis in the direction of its lost point to maintain contact between the wedge surface 11 and lower end of the valve stem and for this purpose a coiled spring 1 i'- is attached at one end to apost 15 on the upper end face of the section 8 and has its other end attached to another post 16 which is secured with the periphery of the section 8 and is adapted to move in a circumferentially elongated recess '17- in the inner wall of the bushing or bearing 9 as shown in Figures 1 and 2.

The construction shown in Figure 4 is similar to that shown in Figures 1 to 3 inclusive except that the lower face of the section -8 and upper face of the section -S are provided with cooperative adjacent wedge surfaces 19- and 19- which are elongated circumferentially.

1n this latter construction the cam flanges -12-- are spaced a relatively shorter distance apart than those shown in Figures 1 and 3 while the offsetmember 10- projecting between said cam flanges is correspondingly narrower.

Operation.

Assuming that the cam shaft 4- is moving in the direction indicated by arrow m, Figures 1 and 2, and that the high point of the cam has just passed from under the bearing member 10 and that the cam surfaces 13 and '13 are just about to engage the adjacent faces of the bearing member -10-- under which conditions the valve -1- will be slightly open.

Then as the cam surfaces 13 and 13- register with opposite sides of the bearing member 10 the engagement of the cam surface -13 with the corresponding side of said bearing member will effect a corresponding angular movement of the tubular member -8 in the direction indicated by arrow y, Figures 1 and 3, thereby causing a lower point of the wedge surface -11 to register with the adjacent end face of the valve stem to allow a corresponding lowering of the valve to its seat by the action of the spring 5, it being understood that this angular motion transmitted to the wedge member 8 is due to the fact that the end thrust friction between the members -8 and 8 is somewhat greater than the friction between the wedge surface -11.- and adjacent end of the valve stem when the point of contact is shifting to a lower part of the wedge surface during which time the contact between the wedge surface 1land valve stem is maintained by the tension spring 14..

Now as the cams 4- and 13- and -13 complete one revolution the remaining portions of the cam surfaces of the members -12- effect an angular movement of the member 8 in the opposite direction thereby placing the spring 14 uncler additional tension to assure the maintenance of contact of the wedge surface 11'- with the lower end of the valve stem.

The operation of the members -8- and -8" by the cam surfaces 13 and -l3 is similar to that previously described except that the wedge surfaces l9 and l9- produces a slightly quicker release on the return movement of the section '8 which release is instantly followed by the angular rotation of the member -8 by the spring 14 to assure a continuous connection between the cam V4 and valve stem and thereby preventing lost motion and noise vincidental thereto.

lVhat I claim is l. The combination with a spring closed poppet valve of an internal combustion engine, a cam shaft, a cam on the shaft, means actuated by the cam for opening the'valve including a wedge engaging the valve stem, a second cam on the shaft, and means actuated by the last-named cam for moving the wedge in the direction of its inclination.

2. The combination with a camshaft and a spring closed valve of an internal combustion engine, a cam on the shaft;"means for maintaining operative connection between the cam and valve including a wedge and a second cam on the shaft for moving the wedge in the direction of its inclination.

3. The combination with a cam shaft and a spring closed valve of an internal combustion engine, a cam on the shaft; means for maintaining operative connection between the cam and valve including a wedge movable about an axis parallel with and at one side of the axis of the valve, and means 1'0- tating with the shaft for efiecting an angular movement of the wedge in the direction of its inclination. V

l. The combination with a cam shaft and a spring closed valve of an internal combustion engine, of a cylindrical "member sup ported in radially ofiset relation to the axis of the valve stem and provided with a wedgesurface in contact with the valve stem at one side of its axis, a cam on the shaft, and means actuated by the cam for effecting an angular movement of the cylindrical member and wedge carried thereby.

In witness whereof I have hereunto set my hand this 15 day of April 1926. WILLIAM M. GOODWIN. 

